Cationic polymers have been used extensively in home and personal care, water treatment, papermaking, mineral processing, petroleum recovery, fabrics, and pharmaceuticals. Among the most important and extensively used cationic polymers are the quaternary ammonium polymers of diallyldialkyl ammonium compounds. In fact, polymers of diallyldimethyl ammonium chloride (DADMAC) are well known in the home and personal care industry as polyquaternium 6, and are used extensively in skin and hair care applications.
The use of homo- and copolymers of diallyldimethylammonium salts in hair care applications has been disclosed in several U.S. Patents.
Most of the currently available cationic polymers provide basic hair conditioning properties, but they also bring along some undesired attributes. One of these undesirable attributes is tackiness. This is also known as a sticky feeling of the polymer on the hair. This undesirable characteristic will cause the hair to clump, causing a decrease in hair volume. It may also weigh down the hair yielding a flattening effect.
The present invention relates to novel water-soluble and cationic copolymers, for example of diallyldimethylammonium chloride (DADMAC) and diallylamine (DAA), that provide excellent conditioning properties and improved tackiness. These copolymers overcome the tacky effect of the typical quaternary ammonium polymers of diallyldialkyl ammonium compounds (polyDADMAC). They also provide an excellent feel with less static fly away. They also contribute useful properties to skin care products.
U.S. Pat. Nos. 3,700,623 and 3,833,531 (assigned to Hercules Inc.) teach making certain acid stabilized poly(diallylamine)-epihalohydrin resins. In a first step a polymer of diallylamine (DAA) was prepared through radical polymerization using a radical initiator. The polymer of diallylamine was then reacted with an epihalohydrin, usually epichlorohydrin (ECH), at a temperature of from about 30 to 80° C. and at a pH of from 7 to 9.5 in aqueous solution. When the viscosity measured on a 20% to 30% solid solution reached a desired viscosity range (A to E on the Gardner-Holdt scale), the product was diluted with water to below 15% solids.
The obtained resin had a tendency to gel on standing. The resin solution was therefore stabilized against gelation by adding enough water-soluble acid (e.g. HCl) to adjust the pH to about 2. The acid-stabilized poly(diallylamine)-epichlorohydrin resins were reactivated prior to use by addition of a base (e.g. NaOH) to adjust pH to above 7. The half-reacted epihalohydrin entities of the alkaline curing resins impart epoxy functionality for crosslinking reactions after being reactivated by addition of alkaline base prior to use. These polymers are insoluble after crosslinking.
U.S. Pat. Nos. 4,354,006, 4,419,498 and 4,419,500 teach a process for making certain poly(DAA-ECH) polymers by reacting a diallylamine (DAA) polymer first with an allyl halide and then with hypohalous acid to convert the allyl substituents to halohydrin moieties.
JP 6,108,382 discloses another way to make certain poly(diallylamine)-epihalohydrin polymers. A diallylamine-epihalohydrin halo salt monomer is first prepared by reacting diallylamine with an epihalohydrin (typically epichlorohydrin) and then neutralizing with a halo acid (typically HCl). The DAA-ECH tertiary amine salt monomer is then polymerized using a radical initiator. The obtained poly(diallyamine)-epihalohydrin polymer is disclosed to provide excellent wet color fastness to a cellulose-based fiber dyed with a direct dye or a reactive dye.
U.S. Pat. No. 5,147,411 discloses a method to prepare the DAA-ECH monomers (3-halo-2-hydroxypropyl)diallylamine and (2,3-epoxypropyl)diallylamine, and their quaternary ammonium salts. The quaternary ammonium DAA-ECH salts are prepared by reacting a DAA-ECH tertiary amine with an alkyl sulfonate. The DAA-ECH quaternary ammonium salts are used directly in treating cellulose fiber material for improved color yield and wet-fastness of dyeing.
U.S. Pat. No. 4,341,887 discloses that the reaction product of diallylamine and epichlorohydrin (3-chloro-2-hydroxypropyl)diallylamine (a DAA-ECH monomer), can be converted to N,N-diallyl-3-hydroxy-azetidinium chloride (DAA-ECH azetidinium monomer) by heating in the presence of water. Removal of the solvent (water) by distillation or freeze drying causes the DAA-ECH azetidinium monomer to reconvert to the linear, non-quaternary N-3-chloro-2-hydroxypropyl-N,N-diallylamine. However (3-chloro-2-hydroxypropyl)diallylamine is not stable for long periods of time and dimerizes to 2,5-bis(diallylaminomethyl)-p-dioxane.
The azetidinium ring remains intact in the polymers obtained by free radical polymerization of the DAA-ECH azetidinium monomer. 1H NMR and 13C NMR were used to identify the azetidinium ring in the monomer and the polymers. The homo- and co-polymers of N,N-diallyl-3-hydroxyazetidinium are useful for demulsification, flocculation and floatation in water treatment.
The above-reviewed patents involve use of an epihalohydrin as a reactive compound to react with DAA monomer or a DAA polymer. Since an epihalohydrin (e.g. epichlorohydrin) is a difunctional reactive crosslinker, highly crosslinked insoluble end products are obtained when fully reacted with equivalent high DAA-containing (i.e. >5%) polymers. In the case where soluble cationic polymers are obtained, the polymers contain half reacted epichlorohydrin with potentially reactive epoxy groups. Only epihalohydrin is disclosed as a cross-linker for diallylamine polymers. Other polyfunctional compounds which could be used to crosslink the diallylamine polymers are not mentioned.
Commonly assigned U.S. Pat. No. 6,323,306, the disclosure of which is incorporated by reference, discloses a method to prepare certain water-soluble cationic polymers by reacting an amino-functionalized DADMAC polymer with a difunctional reactive crosslinker. The reactive crosslinkers include epihalohydrin and other polyfunctional compounds that can be used to cross-link the diallylamine polymers. The patent is limited to a DAA content of less than 5% to prevent formation of undesirable insoluble products which can be caused by excessive crosslinking due to use of the difunctional reactive crosslinker.
Commonly assigned U.S. Pat. No. 6,416,627, the disclosure of which is incorporated by reference, discloses polymeric light stabilizers which contain hindered amine nitroxide, hydroxylamine or hydroxylammonium salt groups, which stabilizers are useful for preventing loss of brightness and for enhancing resistance to yellowing in pulp or paper which still contains lignin. These polymers may be prepared by reacting a polymer containing pendant amino or hydroxyl groups, for example an amino-functionalized DADMAC polymer or a polyamine, with suitable hindered amine educts.